title: Premature luteal regression induced by equine chorionic gonadotropin and estrogen is suppressed by administration of exogenous interferon in red deer (Cervus elaphus).
abstract: Superovulation of red deer hinds with eCG causes premature luteal regression by inducing follicular hypersecretion of estrogen that activates the luteolytic mechanism. Six groups of hinds (n = 8 per group) were treated with progesterone-impregnated intravaginal controlled internal drug-releasing (CIDR) devices for 14 days to synchronize estrus (CIDR device withdrawal = Day 0). Group 1 served as controls; group 2 received an i.m. injection of 1200 IU eCG at -72 h; group 3 received similar eCG treatment as well as i.m. injections of 0.25 mg estradiol benzoate (EDB) at 72, 84, 96, and 108 h; group 4 received twice-daily i.m. injections of 4 mg recombinant bovine interferon-alpha(I)1 (IFN) from Days 2 to 7; group 5 received IFN and eCG as above; group 6 received IFN, eCG, and EDB. Ovarian response was determined by laparoscopy on Days 14 and 15. Progesterone profiles were determined from thrice-weekly plasma samples from Days -14 to 28. Both the incidence of visible signs of luteal regression and the variation in the time of termination of the luteal phase (plasma progesterone < 1 ng/ml) were greater in eCG+EDB-treated hinds than in control, IFN-, IFN+eCG-, and IFN+eCG+EDB-treated hinds (p < 0.05). The ovulation rate in the eCG+EDB-treated hinds was less than that in the eCG-, IFN+eCG-, and IFN+eCG+EDB-treated hinds (p < 0.05). These results suggest that treatment with interferon, the putative embryonic pregnancy recognition signal, suppresses premature luteal regression induced by hypersecretion of estrogen following treatment with eCG.
authors.affiliation: The Zoological Society of London, Institute of Zoology, United Kingdom.
authors.forename: D R
authors.initials: DR
authors.lastname: Bainbridge
authors.forename: D
authors.initials: D
authors.lastname: Deakin
authors.forename: H N
authors.initials: HN
authors.lastname: Jabbour
mesh_terms: D000282:Administration, Intravaginal; D000818:Animals; D002417:Cattle; D003338:Corpus Luteum / Q000187:drug effects / Q000502:physiology; D003670:Deer / Q000502:physiology*; D004958:Estradiol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D005260:Female; D006064:Gonadotropins, Equine / Q000008:administration & dosage / Q000494:pharmacology*; D006736:Horses; D007370:Interferon Type I / Q000494:pharmacology*; D003341:Luteolysis; D011374:Progesterone / Q000097:blood; D011994:Recombinant Proteins
chemical_list: D006064:Gonadotropins, Equine; D007370:Interferon Type I; D011994:Recombinant Proteins; C074283:estradiol 3-benzoate; D011374:Progesterone; D004958:Estradiol